“Those scriptures have been with the church from the beginning, and really the argument is not about the existence of a ‘rapture’ but in the timing or interpretation of that event.”
Yes, those scriptures have been around, but until “rapture” theorists cropped up, everyone correctly understood them to be merely describing the resurrection of the righteous. There is no separate event only for the living described in any of those verses, no matter how hard one tries to twist them to justify it.
This part of the verse is where they get that it is for the living: “we who are alive and remain will be caught up”
The “caught up” part of that verse is what the discussion is all about. It is the word harpazo in Greek which is translated ‘rapturo’ in Latin.
So, a translation of that is: “we who are alive and remain will be ‘rapturo’ed”
I think you can see that this is not a new part of scripture.